Stamp



FIG. 1 is a perspective view of a design for a stamp showing my new design;

FIG. 2 is a front elevation thereof;

FIG. 3 is a side elevation thereof, the side opposite being a mirror image;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The broken line showing of the environment in the figure drawings is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a stamp, as shown and described. 